Main Bearing Bore Alignment

Main bearing bore misalignment may be suspected in cases of premature bearing wear if one bearing wears considerably more than the others or bearings wear cone-shaped.

NOTE: Bearings are not available with oversize outside diameters to allow line boring.

If bearing misalignment is suspected:
1. Acquire a gauge bar the same diameter as the crankshaft journals and which is straight within 0.076 mm (0.003 in.).
2. Put a thin coating of Prussian Blue or similar die on gauge bar.
3. Insert good bearings in block.
4. Insert gauge bar in bearings and rotate one turn.
5. Remove gauge bar.
6. Inspect bearings. Blue die should be deposited evenly on all bearings. If die appears on only one side or bottom of bearing or not at all, block is distorted and should be replaced.